Conventional tree pruning shears are typically provided with a pole of fixed or adjustable length, a shearing mechanism located at one end of the pole, and an operating cable or cord attached to the shearing mechanism and extending the length of the pole for remote operation of the shearing mechanism.
The conventional shearing mechanism usually includes a capturing hook portion which is adapted to hang from a branch or limb intended to be cut, and a mating pivotal cutting blade. The cutting blade includes a leverage arm from which is attached one end of the operating cord. The pruning shears are manipulated by holding the pole in one hand and the operating cord in the other hand . A limb of interest is "hooked" and held by the hook portion of the shearing mechanism. The operating cord is then pulled which causes the cutting blade to pivot into the "captured" limb. The amount of force required to cut the limb varies, depending on the type of wood, the size of the limb and the location of the cut. However, for the most part, the cutting action requires a great deal of force from its operator.
In addition, generally the operating cord hangs freely outside the pole. During the cutting operation, the operating cord will frequently become snagged on other branches or twigs, reducing the cutting force, and requiring time and effort to untangle the operating cord.
Another technical problem to be solved is related to certain user needs for an extendable pruner, that is one which can be extended and locked into a number of effective operating pruner lengths for a pruner having design benefits as described above.
While these other units may be suitable for the particular purpose for which they were intended, or for general use, they would not be as suitable for the purposes nor include the benefits of the present invention as described herein.